Verification Code sent to old device

I want to update my security questions. I keep getting a notice that the verification code is being sent to an iPad I used years and years ago, not to my current cell number (which I've had for 8 years).

I reset my password because I'm fairly certain someone has been attempting to access my log in. Now what do I do? Apple Support has been no help. I can't get a live person on chat or phone :(